#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int mystrlen(char* str)
{
	int count = 0;
	while (count++,*str++)
	{
	}
	return count-1;
}
int main()
{
	char str[] = "this string length is 24";
	int ret = mystrlen(str);
	printf("%d\n", ret);
	return 0;
}